With active route guidance, current infotainment systems remain in a specified follow-up time (of 15 minutes, for example) after a vehicle is switched off. If a vehicle user uses the vehicle key to open one of the vehicle doors or to switch on the ignition within this follow-up time (time frame), only parts of the infotainment system have to be started. After the vehicle key is used, a navigation map is immediately displayed, for example, and the vehicle user can immediately enter a new destination. With this process, the infotainment system is fully booted within about four seconds and offers the user unlimited access to its functions starting from this time. However, if the vehicle user uses the vehicle key outside of the follow-up time to open one of the vehicle doors or to switch on the ignition, the infotainment system will already be in deep-sleep mode and will have to be completely booted up from the deep-sleep state. About 60 to 80 seconds will then be required until complete availability of all functions. Because the vehicle user often returns to the vehicle after the follow-up time and uses the vehicle key, the user must frequently wait 60 to 80 seconds for complete availability of the infotainment system.